Non-small cell lung cancer (NSCLC), is a leading killer of both women and women around the world. Patients with NSCLC are in need of additional therapeutic options. This proposal seeks to examine the cytotoxic T lymphocyte (CTL) response against NSCLC in order to develop novel immunotherapeutic options. The proposal asks questions which will define and characterize the antigens recognized by NSCLC specific CTL. It also will investigate a novel means of presenting NSCLC antigens to lymphocyte precursors. Some or all of the information gleaned may lead to clinical trials of novel immunotherapeutic reagents in NSCLC. Four Specific aims are proposed for study. The first two Specific Aims will identify HLA- A2 restricted NSCLC specific CTL as well as identify and characterize the antigens being recognized. In Specific Aim 3, we will examine the use of other restriction elements beginning with HLA-A3, in the presentation of NSCLC peptides. The identification of NSCLC specific CTL will involve the use of an in vitro co- culture scheme (Mixed lymphocyte tumor cell culture, MLTC) combining lymphocytes obtained from peripheral blood (PBMC) of normal donors and NSCLC patients with HLA-A locus matched allogeneic long term NSCLC tumor cell lines. The NSCLC lines are gene modified to express the lymphocyte co-stimulatory molecule, CD80 (B7.1). Thus, the tumor cells bearing class I MHC molecules and potential tumor antigens will be made into efficient presenting cells. Identification of CTL defined antigens in Specific Aim 2 will be done using molecular biologic techniques and existing gene- cloning strategies. While we present preliminary data showing that we can successfully generate HLA-A2 specific CTL using the described system, Specific Aim 4 proposes to study an alternative and possibly more efficient means of NSCLC antigen presentation. Fusions are proposed between NSCLC tumor cell lines and dendritic cells. Resultant somatic cell hybrids will be used to generate specific CTL in vitro. These attempts to generate specific CTL in NSCLC will add greatly to our knowledge base of the immunological response to this disease as well as provide critical reagents for vaccine or cellular immunotherapy protocols.